scholarly journals Novel black-bounce spacetimes: Wormholes, regularity, energy conditions, and causal structure

2021 ◽  
Vol 103 (8) ◽  
Author(s):  
Francisco S. N. Lobo ◽  
Manuel E. Rodrigues ◽  
Marcos V. de S. Silva ◽  
Alex Simpson ◽  
Matt Visser
Keyword(s):  
Causal Structure ◽  
Energy Conditions

An intrinsic conformal Lorentz pseudodistance

1981 ◽  
Vol 89 (2) ◽  
pp. 359-371 ◽  
Author(s):  
Michael J Markowitz
Keyword(s):  
Exact Solutions ◽  
Hyperbolic Space ◽  
Causal Structure ◽  
Sufficient Conditions ◽  
Lorentzian Manifold ◽  
Energy Conditions ◽  
Einstein Field Equations ◽  
Field Equations ◽  
True Distance ◽  
Reasonable Energy

AbstractAn intrinsic pseudodistance dM is associated to the underlying causal structure of a Lorentzian manifold (M, g). An infinitesimal form for dM is defined on the bundle of null vectors over M and is used to prove that, under certain physically reasonable energy conditions, M is conformally hyperbolic, i.e. that dM is a true distance. As a corollary we obtain sufficient conditions for the conformal hyperbolicity of a globally hyperbolic space-time. Some exact solutions of the Einstein field equations are discussed and possible applications to the study of singularities are outlined.

Special, radical, failure of reduction in psychiatry

2019 ◽  
Vol 42 ◽  
Author(s):  
Don Ross
Keyword(s):  
Mental Disorder ◽  
Brain Structure ◽  
Causal Structure ◽  
Network Models ◽  
Gambling Addiction ◽  
Brain Disorder ◽  
Mental Processes ◽  
Special Radical ◽  
Intentional Relationships

AbstractUse of network models to identify causal structure typically blocks reduction across the sciences. Entanglement of mental processes with environmental and intentional relationships, as Borsboom et al. argue, makes reduction of psychology to neuroscience particularly implausible. However, in psychiatry, a mental disorder can involve no brain disorder at all, even when the former crucially depends on aspects of brain structure. Gambling addiction constitutes an example.

Blocking Is Sensitive to Causal Structure in 4-Year-Old and 8-Year-Old Children

2005 ◽  
Vol 52 (4) ◽  
pp. 264-271 ◽  
Author(s):  
Tom Beckers ◽  
Uschi Van den Broeck ◽  
Marij Renne ◽  
Stefaan Vandorpe ◽  
Jan De Houwer ◽  
...  
Keyword(s):  
Young Children ◽  
Associative Learning ◽  
Learning Theory ◽  
Causal Structure ◽  
Age Groups ◽  
Learning Task ◽  
Contingency Learning

Abstract. In a contingency learning task, 4-year-old and 8-year-old children had to predict the outcome displayed on the back of a card on the basis of cues presented on the front. The task was embedded in either a causal or a merely predictive scenario. Within this task, either a forward blocking or a backward blocking procedure was implemented. Blocking occurred in the causal but not in the predictive scenario. Moreover, blocking was affected by the scenario to the same extent in both age groups. The pattern of results was similar for forward and backward blocking. These results suggest that even young children are sensitive to the causal structure of a contingency learning task and that the occurrence of blocking in such a task defies an explanation in terms of associative learning theory.

Institutional actors: Children’s emerging beliefs about the causal structure of social roles.

2020 ◽  
Vol 56 (1) ◽  
pp. 70-80
Author(s):  
Alexander Noyes ◽  
Frank C. Keil ◽  
Yarrow Dunham
Keyword(s):  
Social Roles ◽  
Causal Structure ◽  
Institutional Actors

Incompleteness of General Relativity, Einstein's Errors, and Related Experiments-- American Physical Society March meeting, Z23 5, 2015 --

2015 ◽  
Vol 8 (2) ◽  
pp. 2135-2147 ◽  
Author(s):  
C. Y. Lo
Keyword(s):  
General Relativity ◽  
Einstein Equation ◽  
Reaction Force ◽  
Radiation Reaction ◽  
Gravitational Energy ◽  
Energy Conditions ◽  
Experimental Investigations ◽  
Positive Mass Theorem ◽  
Wave Source ◽  
Photonic Energy

General relativity is incomplete since it does not include the gravitational radiation reaction force and the interaction of gravitation with charged particles. General relativity is confusing because Einstein's covariance principle is invalid in physics. Moreover, there is no bounded dynamic solution for the Einstein equation. Thus, Gullstrand is right and the 1993 Nobel Prize for Physics press release is incorrect. Moreover, awards to Christodoulou reflect the blind faith toward Einstein and accumulated errors in mathematics. Note that the Einstein equation with an electromagnetic wave source has no valid solution unless a photonic energy-stress tensor with an anti-gravitational coupling is added. Thus, the photonic energy includes gravitational energy. The existence of anti-gravity coupling implies that the energy conditions in space-time singularity theorems of Hawking and Penrose cannot be satisfied, and thus are irrelevant. Also, the positive mass theorem of Yau and Schoen is misleading, though considered as an achievement by the Fields Medal. E = mc2 is invalid for the electromagnetic energy alone. The discovery of the charge-mass interaction establishes the need for unification of electromagnetism and gravitation and would explain many puzzles. Experimental investigations for further results are important.

Institutional actors: Children’s emerging beliefs about the causal structure of social roles

2019 ◽  
Author(s):  
Alexander Noyes ◽  
Frank Keil ◽  
Yarrow Dunham
Keyword(s):  
Soccer Player ◽  
Social Roles ◽  
Social Role ◽  
Causal Structure ◽  
Executive Orders ◽  
The Social ◽  
The World ◽  
Children's Beliefs ◽  
Institutional Actors ◽  
The U.S

Institutions make new forms of acting possible: Signing executive orders, scoring goals, and officiating weddings are only possible because of the U.S. government, the rules of soccer, and the institution of marriage. Thus, when an individual occupies a particular social role (President, soccer player, and officiator) they acquire new ways of acting on the world. The present studies investigated children’s beliefs about institutional actions, and in particular whether children understand that individuals can only perform institutional actions when their community recognizes them as occupying the appropriate social role. Two studies (Study 1, N = 120 children, 4-11; Study 2, N = 90 children, 4-9) compared institutional actions to standard actions that do not depend on institutional recognition. In both studies, 4- to 5-year-old children believed all actions were possible regardless of whether an individual was recognized as occupying the social role. In contrast, 8- to 9-year-old children robustly distinguished between institutional and standard actions; they understood that institutional actions depend on collective recognition by a community.

Sign in / Sign up

Export Citation Format

Share Document